/*
 * Copyright 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*namespace com.google.zxing.qrcode.encoder {*/

import EncodeHintType from './../../EncodeHintType'
import BitArray from './../../common/BitArray'
import CharacterSetECI from './../../common/CharacterSetECI'
import GenericGF from './../../common/reedsolomon/GenericGF'
import ReedSolomonEncoder from './../../common/reedsolomon/ReedSolomonEncoder'
import ErrorCorrectionLevel from './../decoder/ErrorCorrectionLevel'
import Mode from './../decoder/Mode'
import Version from './../decoder/Version'
import MaskUtil from './MaskUtil'
import ByteMatrix from './ByteMatrix'
import QRCode from './QRCode'
import Exception from './../../Exception'
import ECBlocks from './../decoder/ECBlocks'
import MatrixUtil from './MatrixUtil'
import StringEncoding from './../../util/StringEncoding'
import BlockPair from './BlockPair'

/*import java.io.UnsupportedEncodingException;*/
/*import java.util.ArrayList;*/
/*import java.util.Collection;*/
/*import java.util.Map;*/

/**
 * @author satorux@google.com (Satoru Takabayashi) - creator
 * @author dswitkin@google.com (Daniel Switkin) - ported from C++
 */
export default class Encoder {

  // The original table is defined in the table 5 of JISX0510:2004 (p.19).
  private static ALPHANUMERIC_TABLE = Int32Array.from([
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 0x00-0x0f
      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 0x10-0x1f
      36, -1, -1, -1, 37, 38, -1, -1, -1, -1, 39, 40, -1, 41, 42, 43,  // 0x20-0x2f
      0,   1,  2,  3,  4,  5,  6,  7,  8,  9, 44, -1, -1, -1, -1, -1,  // 0x30-0x3f
      -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,  // 0x40-0x4f
      25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, -1,  // 0x50-0x5f
  ])

  public static DEFAULT_BYTE_MODE_ENCODING = CharacterSetECI.UTF8.getName()//"ISO-8859-1"
  // TYPESCRIPTPORT: changed to UTF8, the default for js

  private constructor() {}

  // The mask penalty calculation is complicated.  See Table 21 of JISX0510:2004 (p.45) for details.
  // Basically it applies four rules and summate all penalties.
  private static calculateMaskPenalty(matrix: ByteMatrix): number /*int*/ {
    return MaskUtil.applyMaskPenaltyRule1(matrix)
        + MaskUtil.applyMaskPenaltyRule2(matrix)
        + MaskUtil.applyMaskPenaltyRule3(matrix)
        + MaskUtil.applyMaskPenaltyRule4(matrix)
  }

  /**
   * @param content text to encode
   * @param ecLevel error correction level to use
   * @return {@link QRCode} representing the encoded QR code
   * @throws WriterException if encoding can't succeed, because of for example invalid content
   *   or configuration
   */
  // public static encode(content: string, ecLevel: ErrorCorrectionLevel): QRCode /*throws WriterException*/ {
  //   return encode(content, ecLevel, null)
  // }

  public static encode(content: string,
                              ecLevel: ErrorCorrectionLevel,
                              hints: Map<EncodeHintType, any> = null): QRCode /*throws WriterException*/ {

    // Determine what character encoding has been specified by the caller, if any
    let encoding: string = Encoder.DEFAULT_BYTE_MODE_ENCODING
    const hasEncodingHint: boolean = hints !== null && undefined !== hints.get(EncodeHintType.CHARACTER_SET)
    if (hasEncodingHint) {
      encoding = hints.get(EncodeHintType.CHARACTER_SET).toString()
    }

    // Pick an encoding mode appropriate for the content. Note that this will not attempt to use
    // multiple modes / segments even if that were more efficient. Twould be nice.
    const mode: Mode = this.chooseMode(content, encoding)

    // This will store the header information, like mode and
    // length, as well as "header" segments like an ECI segment.
    const headerBits = new BitArray()

    // Append ECI segment if applicable
    if (mode == Mode.BYTE && (hasEncodingHint || Encoder.DEFAULT_BYTE_MODE_ENCODING !== encoding)) {
      const eci = CharacterSetECI.getCharacterSetECIByName(encoding)
      if (eci !== undefined) {
        this.appendECI(eci, headerBits)
      }
    }

    // (With ECI in place,) Write the mode marker
    this.appendModeInfo(mode, headerBits)

    // Collect data within the main segment, separately, to count its size if needed. Don't add it to
    // main payload yet.
    const dataBits = new BitArray()
    this.appendBytes(content, mode, dataBits, encoding)

    let version: Version
    if (hints !== null && undefined !== hints.get(EncodeHintType.QR_VERSION)) {
      const versionNumber = Number.parseInt(hints.get(EncodeHintType.QR_VERSION).toString(), 10)
      version = Version.getVersionForNumber(versionNumber)
      const bitsNeeded = this.calculateBitsNeeded(mode, headerBits, dataBits, version)
      if (!this.willFit(bitsNeeded, version, ecLevel)) {
        throw new Exception(Exception.WriterException, "Data too big for requested version")
      }
    } else {
      version = this.recommendVersion(ecLevel, mode, headerBits, dataBits)
    }

    const headerAndDataBits = new BitArray()
    headerAndDataBits.appendBitArray(headerBits)
    // Find "length" of main segment and write it
    const numLetters = mode == Mode.BYTE ? dataBits.getSizeInBytes() : content.length
    this.appendLengthInfo(numLetters, version, mode, headerAndDataBits)
    // Put data together into the overall payload
    headerAndDataBits.appendBitArray(dataBits)

    const ecBlocks: ECBlocks = version.getECBlocksForLevel(ecLevel)
    const numDataBytes = version.getTotalCodewords() - ecBlocks.getTotalECCodewords()

    // Terminate the bits properly.
    this.terminateBits(numDataBytes, headerAndDataBits)

    // Interleave data bits with error correction code.
    const finalBits: BitArray = this.interleaveWithECBytes(headerAndDataBits,
                                               version.getTotalCodewords(),
                                               numDataBytes,
                                               ecBlocks.getNumBlocks())

    const qrCode = new QRCode()

    qrCode.setECLevel(ecLevel)
    qrCode.setMode(mode)
    qrCode.setVersion(version)

    //  Choose the mask pattern and set to "qrCode".
    const dimension = version.getDimensionForVersion()
    const matrix: ByteMatrix = new ByteMatrix(dimension, dimension)
    const maskPattern = this.chooseMaskPattern(finalBits, ecLevel, version, matrix)
    qrCode.setMaskPattern(maskPattern)

    // Build the matrix and set it to "qrCode".
    MatrixUtil.buildMatrix(finalBits, ecLevel, version, maskPattern, matrix)
    qrCode.setMatrix(matrix)

    return qrCode
  }

  /**
   * Decides the smallest version of QR code that will contain all of the provided data.
   *
   * @throws WriterException if the data cannot fit in any version
   */
  private static recommendVersion(ecLevel: ErrorCorrectionLevel,
                                          mode: Mode,
                                          headerBits: BitArray,
                                          dataBits: BitArray): Version /*throws WriterException*/ {
    // Hard part: need to know version to know how many bits length takes. But need to know how many
    // bits it takes to know version. First we take a guess at version by assuming version will be
    // the minimum, 1:
    const provisionalBitsNeeded = this.calculateBitsNeeded(mode, headerBits, dataBits, Version.getVersionForNumber(1))
    const provisionalVersion = this.chooseVersion(provisionalBitsNeeded, ecLevel)

    // Use that guess to calculate the right version. I am still not sure this works in 100% of cases.
    const bitsNeeded = this.calculateBitsNeeded(mode, headerBits, dataBits, provisionalVersion)
    return this.chooseVersion(bitsNeeded, ecLevel)
  }

  private static calculateBitsNeeded(mode: Mode,
                                        headerBits: BitArray,
                                        dataBits: BitArray,
                                        version: Version): number /*int*/ {
    return headerBits.getSize() + mode.getCharacterCountBits(version) + dataBits.getSize()
  }

  /**
   * @return the code point of the table used in alphanumeric mode or
   *  -1 if there is no corresponding code in the table.
   */
  public static getAlphanumericCode(code: number /*int*/): number /*int*/ {
    if (code < Encoder.ALPHANUMERIC_TABLE.length) {
      return Encoder.ALPHANUMERIC_TABLE[code]
    }
    return -1
  }

  // public static chooseMode(content: string): Mode {
  //   return chooseMode(content, null);
  // }

  /**
   * Choose the best mode by examining the content. Note that 'encoding' is used as a hint;
   * if it is Shift_JIS, and the input is only double-byte Kanji, then we return {@link Mode#KANJI}.
   */
  public static chooseMode(content: string, encoding: string = null): Mode {
    if (CharacterSetECI.SJIS.getName() === encoding && this.isOnlyDoubleByteKanji(content)) {
      // Choose Kanji mode if all input are double-byte characters
      return Mode.KANJI
    }
    let hasNumeric: boolean = false
    let hasAlphanumeric: boolean = false
    for (let i = 0, length = content.length; i < length; ++i) {
      const c: string = content.charAt(i)
      if (Encoder.isDigit(c)) {
        hasNumeric = true
      } else if (this.getAlphanumericCode(c.charCodeAt(0)) != -1) {
        hasAlphanumeric = true
      } else {
        return Mode.BYTE
      }
    }
    if (hasAlphanumeric) {
      return Mode.ALPHANUMERIC
    }
    if (hasNumeric) {
      return Mode.NUMERIC
    }
    return Mode.BYTE
  }

  private static isOnlyDoubleByteKanji(content: string): boolean {
    let bytes: Uint8Array
    try {
      bytes = StringEncoding.encode(content, CharacterSetECI.SJIS.getName())//content.getBytes("Shift_JIS")
    } catch (ignored/*: UnsupportedEncodingException*/) {
      return false
    }
    const length = bytes.length
    if (length % 2 != 0) {
      return false
    }
    for (let i = 0; i < length; i += 2) {
      const byte1 = bytes[i] & 0xFF
      if ((byte1 < 0x81 || byte1 > 0x9F) && (byte1 < 0xE0 || byte1 > 0xEB)) {
        return false
      }
    }
    return true
  }

  private static chooseMaskPattern(bits: BitArray,
                                       ecLevel: ErrorCorrectionLevel,
                                       version: Version,
                                       matrix: ByteMatrix): number /*int*/ /*throws WriterException*/ {

    let minPenalty = Number.MAX_SAFE_INTEGER;  // Lower penalty is better.
    let bestMaskPattern = -1
    // We try all mask patterns to choose the best one.
    for (let maskPattern = 0; maskPattern < QRCode.NUM_MASK_PATTERNS; maskPattern++) {
      MatrixUtil.buildMatrix(bits, ecLevel, version, maskPattern, matrix)
      let penalty = this.calculateMaskPenalty(matrix)
      if (penalty < minPenalty) {
        minPenalty = penalty
        bestMaskPattern = maskPattern
      }
    }
    return bestMaskPattern
  }

  private static chooseVersion(numInputBits: number /*int*/, ecLevel: ErrorCorrectionLevel): Version /*throws WriterException*/ {
    for (let versionNum = 1; versionNum <= 40; versionNum++) {
      const version = Version.getVersionForNumber(versionNum)
      if (Encoder.willFit(numInputBits, version, ecLevel)) {
        return version
      }
    }
    throw new Exception(Exception.WriterException, "Data too big")
  }
  
  /**
   * @return true if the number of input bits will fit in a code with the specified version and
   * error correction level.
   */
  private static willFit(numInputBits: number /*int*/, version: Version, ecLevel: ErrorCorrectionLevel): boolean {
      // In the following comments, we use numbers of Version 7-H.
      // numBytes = 196
      const numBytes = version.getTotalCodewords()
      // getNumECBytes = 130
      const ecBlocks = version.getECBlocksForLevel(ecLevel)
      const numEcBytes = ecBlocks.getTotalECCodewords()
      // getNumDataBytes = 196 - 130 = 66
      const numDataBytes = numBytes - numEcBytes
      const totalInputBytes = (numInputBits + 7) / 8
      return numDataBytes >= totalInputBytes
  }

  /**
   * Terminate bits as described in 8.4.8 and 8.4.9 of JISX0510:2004 (p.24).
   */
  public static terminateBits(numDataBytes: number /*int*/, bits: BitArray): void /*throws WriterException*/ {
    const capacity = numDataBytes * 8;
    if (bits.getSize() > capacity) {
      throw new Exception(Exception.WriterException, "data bits cannot fit in the QR Code" + bits.getSize() + " > " +
          capacity)
    }
    for (let i = 0; i < 4 && bits.getSize() < capacity; ++i) {
      bits.appendBit(false)
    }
    // Append termination bits. See 8.4.8 of JISX0510:2004 (p.24) for details.
    // If the last byte isn't 8-bit aligned, we'll add padding bits.
    const numBitsInLastByte = bits.getSize() & 0x07;    
    if (numBitsInLastByte > 0) {
      for (let i = numBitsInLastByte; i < 8; i++) {
        bits.appendBit(false)
      }
    }
    // If we have more space, we'll fill the space with padding patterns defined in 8.4.9 (p.24).
    const numPaddingBytes = numDataBytes - bits.getSizeInBytes()
    for (let i = 0; i < numPaddingBytes; ++i) {
      bits.appendBits((i & 0x01) == 0 ? 0xEC : 0x11, 8)
    }
    if (bits.getSize() != capacity) {
      throw new Exception(Exception.WriterException, "Bits size does not equal capacity")
    }
  }

  /**
   * Get number of data bytes and number of error correction bytes for block id "blockID". Store
   * the result in "numDataBytesInBlock", and "numECBytesInBlock". See table 12 in 8.5.1 of
   * JISX0510:2004 (p.30)
   */
  public static getNumDataBytesAndNumECBytesForBlockID(numTotalBytes: number /*int*/,
                                                        numDataBytes: number /*int*/,
                                                        numRSBlocks: number /*int*/,
                                                        blockID: number /*int*/,
                                                        numDataBytesInBlock: Int32Array,
                                                        numECBytesInBlock: Int32Array): void /*throws WriterException*/ {
    if (blockID >= numRSBlocks) {
      throw new Exception(Exception.WriterException, "Block ID too large")
    }
    // numRsBlocksInGroup2 = 196 % 5 = 1
    const numRsBlocksInGroup2 = numTotalBytes % numRSBlocks
    // numRsBlocksInGroup1 = 5 - 1 = 4
    const numRsBlocksInGroup1 = numRSBlocks - numRsBlocksInGroup2
    // numTotalBytesInGroup1 = 196 / 5 = 39
    const numTotalBytesInGroup1 = Math.floor(numTotalBytes / numRSBlocks)
    // numTotalBytesInGroup2 = 39 + 1 = 40
    const numTotalBytesInGroup2 = numTotalBytesInGroup1 + 1
    // numDataBytesInGroup1 = 66 / 5 = 13
    const numDataBytesInGroup1 = Math.floor(numDataBytes / numRSBlocks)
    // numDataBytesInGroup2 = 13 + 1 = 14
    const numDataBytesInGroup2 = numDataBytesInGroup1 + 1
    // numEcBytesInGroup1 = 39 - 13 = 26
    const numEcBytesInGroup1 = numTotalBytesInGroup1 - numDataBytesInGroup1
    // numEcBytesInGroup2 = 40 - 14 = 26
    const numEcBytesInGroup2 = numTotalBytesInGroup2 - numDataBytesInGroup2
    // Sanity checks.
    // 26 = 26
    if (numEcBytesInGroup1 !== numEcBytesInGroup2) {
      throw new Exception(Exception.WriterException, "EC bytes mismatch")
    }
    // 5 = 4 + 1.
    if (numRSBlocks !== numRsBlocksInGroup1 + numRsBlocksInGroup2) {
      throw new Exception(Exception.WriterException, "RS blocks mismatch")
    }
    // 196 = (13 + 26) * 4 + (14 + 26) * 1
    if (numTotalBytes !==
        ((numDataBytesInGroup1 + numEcBytesInGroup1) *
            numRsBlocksInGroup1) +
            ((numDataBytesInGroup2 + numEcBytesInGroup2) *
                numRsBlocksInGroup2)) {
      throw new Exception(Exception.WriterException, "Total bytes mismatch")
    }

    if (blockID < numRsBlocksInGroup1) {
      numDataBytesInBlock[0] = numDataBytesInGroup1
      numECBytesInBlock[0] = numEcBytesInGroup1
    } else {
      numDataBytesInBlock[0] = numDataBytesInGroup2
      numECBytesInBlock[0] = numEcBytesInGroup2
    }
  }

  /**
   * Interleave "bits" with corresponding error correction bytes. On success, store the result in
   * "result". The interleave rule is complicated. See 8.6 of JISX0510:2004 (p.37) for details.
   */
  public static interleaveWithECBytes(bits: BitArray,
                                        numTotalBytes: number /*int*/,
                                        numDataBytes: number /*int*/,
                                        numRSBlocks: number /*int*/): BitArray /*throws WriterException*/ {

    // "bits" must have "getNumDataBytes" bytes of data.
    if (bits.getSizeInBytes() !== numDataBytes) {
      throw new Exception(Exception.WriterException, "Number of bits and data bytes does not match")
    }

    // Step 1.  Divide data bytes into blocks and generate error correction bytes for them. We'll
    // store the divided data bytes blocks and error correction bytes blocks into "blocks".
    let dataBytesOffset = 0
    let maxNumDataBytes = 0
    let maxNumEcBytes = 0

    // Since, we know the number of reedsolmon blocks, we can initialize the vector with the number.
    const blocks = new Array<BlockPair>()//new Array<BlockPair>(numRSBlocks)

    for (let i = 0; i < numRSBlocks; ++i) {
      const numDataBytesInBlock: Int32Array = new Int32Array(1)
      const numEcBytesInBlock: Int32Array = new Int32Array(1)
      Encoder.getNumDataBytesAndNumECBytesForBlockID(
          numTotalBytes, numDataBytes, numRSBlocks, i,
          numDataBytesInBlock, numEcBytesInBlock)

      const size = numDataBytesInBlock[0]
      const dataBytes = new Uint8Array(size)
      bits.toBytes(8 * dataBytesOffset, dataBytes, 0, size);
      const ecBytes: Uint8Array = Encoder.generateECBytes(dataBytes, numEcBytesInBlock[0])
      blocks.push(new BlockPair(dataBytes, ecBytes))

      maxNumDataBytes = Math.max(maxNumDataBytes, size)
      maxNumEcBytes = Math.max(maxNumEcBytes, ecBytes.length)
      dataBytesOffset += numDataBytesInBlock[0]
    }
    if (numDataBytes != dataBytesOffset) {
      throw new Exception(Exception.WriterException, "Data bytes does not match offset")
    }

    const result = new BitArray()

    // First, place data blocks.
    for (let i = 0; i < maxNumDataBytes; ++i) {
      for (const block of blocks) {
        const dataBytes = block.getDataBytes()
        if (i < dataBytes.length) {
          result.appendBits(dataBytes[i], 8)
        }
      }
    }
    // Then, place error correction blocks.
    for (let i = 0; i < maxNumEcBytes; ++i) {
      for (const block of blocks) {
        const ecBytes = block.getErrorCorrectionBytes()
        if (i < ecBytes.length) {
          result.appendBits(ecBytes[i], 8)
        }
      }
    }
    if (numTotalBytes != result.getSizeInBytes()) {  // Should be same.
      throw new Exception("WriterException", "Interleaving error: " + numTotalBytes + " and " +
          result.getSizeInBytes() + " differ.")
    }

    return result
  }

  public static generateECBytes(dataBytes: Uint8Array, numEcBytesInBlock: number /*int*/): Uint8Array {
    const numDataBytes = dataBytes.length
    const toEncode: Int32Array = new Int32Array(numDataBytes + numEcBytesInBlock)//int[numDataBytes + numEcBytesInBlock]
    for (let i = 0; i < numDataBytes; i++) {
      toEncode[i] = dataBytes[i] & 0xFF
    }
    new ReedSolomonEncoder(GenericGF.QR_CODE_FIELD_256).encode(toEncode, numEcBytesInBlock)

    const ecBytes = new Uint8Array(numEcBytesInBlock)
    for (let i = 0; i < numEcBytesInBlock; i++) {
      ecBytes[i] = /*(byte) */toEncode[numDataBytes + i]
    }
    return ecBytes
  }

  /**
   * Append mode info. On success, store the result in "bits".
   */
  public static appendModeInfo(mode: Mode, bits: BitArray): void {
    bits.appendBits(mode.getBits(), 4)
  }


  /**
   * Append length info. On success, store the result in "bits".
   */
  public static appendLengthInfo(numLetters: number /*int*/, version: Version, mode: Mode, bits: BitArray): void /*throws WriterException*/ {
    const numBits = mode.getCharacterCountBits(version)
    if (numLetters >= (1 << numBits)) {
      throw new Exception(Exception.WriterException, numLetters + " is bigger than " + ((1 << numBits) - 1))
    }
    bits.appendBits(numLetters, numBits)
  }

  /**
   * Append "bytes" in "mode" mode (encoding) into "bits". On success, store the result in "bits".
   */
  public static appendBytes(content: string,
                          mode: Mode,
                          bits: BitArray,
                          encoding: string): void /*throws WriterException*/ {
    switch (mode) {
      case Mode.NUMERIC:
        Encoder.appendNumericBytes(content, bits)
        break
      case Mode.ALPHANUMERIC:
        Encoder.appendAlphanumericBytes(content, bits)
        break
      case Mode.BYTE:
        Encoder.append8BitBytes(content, bits, encoding)
        break
      case Mode.KANJI:
        Encoder.appendKanjiBytes(content, bits)
        break
      default:
        throw new Exception(Exception.WriterException, "Invalid mode: " + mode)
    }
  }

  private static getDigit(singleCharacter: string): number {
      return singleCharacter.charCodeAt(0) - 48
  }

  private static isDigit(singleCharacter: string): boolean {
    const cn = Encoder.getDigit(singleCharacter)
    return cn >= 0 && cn <= 9
  }

  public static appendNumericBytes(content: string, bits: BitArray): void {
    const length = content.length
    let i = 0
    while (i < length) {
      const num1 = Encoder.getDigit(content.charAt(i))
      if (i + 2 < length) {
        // Encode three numeric letters in ten bits.
        const num2 = Encoder.getDigit(content.charAt(i + 1))
        const num3 = Encoder.getDigit(content.charAt(i + 2))
        bits.appendBits(num1 * 100 + num2 * 10 + num3, 10)
        i += 3
      } else if (i + 1 < length) {
        // Encode two numeric letters in seven bits.
        const num2 = Encoder.getDigit(content.charAt(i + 1))
        bits.appendBits(num1 * 10 + num2, 7);
        i += 2
      } else {
        // Encode one numeric letter in four bits.
        bits.appendBits(num1, 4)
        i++
      }
    }
  }

  public static appendAlphanumericBytes(content: string, bits: BitArray): void /*throws WriterException*/ {
    const length = content.length
    let i = 0
    while (i < length) {
      const code1 = Encoder.getAlphanumericCode(content.charCodeAt(i))
      if (code1 == -1) {
        throw new Exception(Exception.WriterException)
      }
      if (i + 1 < length) {
        const code2 = Encoder.getAlphanumericCode(content.charCodeAt(i + 1))
        if (code2 == -1) {
          throw new Exception(Exception.WriterException)
        }
        // Encode two alphanumeric letters in 11 bits.
        bits.appendBits(code1 * 45 + code2, 11);
        i += 2
      } else {
        // Encode one alphanumeric letter in six bits.
        bits.appendBits(code1, 6)
        i++
      }
    }
  }

  public static append8BitBytes(content: string, bits: BitArray, encoding: string): void
      /*throws WriterException*/ {
    let bytes: Uint8Array
    try {
      bytes = StringEncoding.encode(content, encoding)
    } catch (uee/*: UnsupportedEncodingException*/) {
      throw new Exception(Exception.WriterException, uee)
    }
    for (let i = 0, length = bytes.length; i != length; i++) {
      const b = bytes[i]
      bits.appendBits(b, 8)
    }
  }

  public static appendKanjiBytes(content: string, bits: BitArray): void /*throws WriterException*/ {
    let bytes: Uint8Array
    try {
      bytes = StringEncoding.encode(content, CharacterSetECI.SJIS.getName())
    } catch (uee/*: UnsupportedEncodingException*/) {
      throw new Exception(Exception.WriterException, uee)
    }
    const length = bytes.length
    for (let i = 0; i < length; i += 2) {
      const byte1 = bytes[i] & 0xFF
      const byte2 = bytes[i + 1] & 0xFF
      const code = ((byte1 << 8) & 0xFFFFFFFF) | byte2
      let subtracted = -1
      if (code >= 0x8140 && code <= 0x9ffc) {
        subtracted = code - 0x8140
      } else if (code >= 0xe040 && code <= 0xebbf) {
        subtracted = code - 0xc140
      }
      if (subtracted === -1) {
        throw new Exception(Exception.WriterException, "Invalid byte sequence")
      }
      const encoded = ((subtracted >> 8) * 0xc0) + (subtracted & 0xff);
      bits.appendBits(encoded, 13)
    }
  }

  private static appendECI(eci: CharacterSetECI, bits: BitArray): void {
    bits.appendBits(Mode.ECI.getBits(), 4)
    // This is correct for values up to 127, which is all we need now.
    bits.appendBits(eci.getValue(), 8)
  }

}
